Apparatus for controlling tension in warp yarns



Oct. 16, 1951 T. J. WILLIS ET AL 0 APPARATUS FOR CONTROLLING TENSION IN WARP YARNS Filed Aug. 15, 1950 5 Sheets-Sheet 1 I INVENTORS M/ILL/AM A 4 SMITH- BY J EJ M ATTORNEYS.

Oct. 16, 1951 T. J. WILLIS ET AL 2,571,509

APPARATUS FOR CONTROLLING TENSION IN wARR YARNs Filed Aug. 15, 1950 5 Sheets-Sheet 2 filo/144s d MLL/S 5 MAL/AM A SM/THJ INVENTORS' ATTORNEYS Oct. 16, 1951 T. J. WILLIS ETAL APPARATUS FOR CONTROLLING TENSION IN WARP YARNS 5 Sheets-Sheet 5 Filed Aug. 15 1950 INVENTOR 7Z/0MAs J MAL/3,6

ATTORNEYS.

IllllllllHl Oct. 16, 1951 2,571,509

APPARATUS FOR CONTROLLING TENSION IN WARP YARNS T. J. WILLIS ET AL Filed Aug. 15, 1950 5 Sheets-Sheet 4 72 445 J. MAL/S INVENTORS.

BY M 'M ATTORNEYS,

T. .1. WILLIS ET AL Get. 16, 1951 2,571,509

APPARATUS FOR CONTROLLING TENSION IN WARP YARNS Filed Aug. 15, 1950 5 Sheets-Sheet 5 MAL/AM 4. SMITH- ATTORNEYS Patented Oct. 16, 1951 UNITED STATES PATENT OFFICE APPARATUS FOR CONTROLLING TENSION IN WARP YARNS Thomas J. Willis and William .A. Smith, Qreenwood, S. 0,

Application August 15, 1950, Serial No. 179,544

6.0laims. 1

"Th e t o elates to te ile mac in e d more especia y to an m r ed were w r tension apparatus controlled by the shipper handle no n m ment h r of in s a ti an p i the loom.

In weaving certain types of cloth where a pinrality of harnesses are used andsome of thehar- :nesses are down a zsem arenp when th ieei stop the harnesses in the he ree t n a subject to considerably more tension than those harnesses in the down position because the harnesses-in the up position are farther awe-y from the center line of the warp line than those in the down position. The tension on the up harnesses t nds t stretch th ya n n th s h rness s t such an extent that when the 10 m isstarted this yarn which has been stretched weaves into the fabric loosely making what is commonly known .as set-marks or rid esand a washboard effect is produced in the fabric upon starting the loom.

It is therefore, the primary object of this invention-to provide an improved tension supplying means responsive to movement of the shipper handle of the loom for applying a normal tension to the warp yarns simultaneously with the loom being started and, simultaneously with the loom being stopped, means are provided for releasing said tension applying means so as to relax the warp yarns between their points of suspension during periods in-which'the'lopm is-not operating.

It is another object ofthisinvention-to provide an improved means for releasing tension on warp ya ns n a l om, 5 1 s in he oom, comprising a pair of closely spaced stationary shafts ,orba-rs disposed rearwardlyof the usual whip roll -of the loom, these shafts being mounted incommon pivoted members or cradles which are pivotally supported on the loom, and to further provide means au m ically oper ble uponym ve- -ment of the shipper handle of the loom for imparting movement to the pivoted -znembersand, thus, to the shafts carried-thereby, the warp yarns being adapted to pass upwardly from the warp beam over the first of said shafts and beneath the second of said shafts and then Over the whip .-ro l wh r by, up n mov men o th pi oted mem e n one dire tion, the shaf s le eat tension on the warp yarns and, upon of the piv t d members inthe op o ite; v th shafts will releas th te i n on th war yarns Some of the Qbieets of th inventi n havin :b en sta d eth rts w a pea as h eseriptionrre eed w n t e i eqhne iehw th thezaeeompanyin drawi :i .whi h= Figure 1 is a side elevation of aloom with parts broken away and showing the invention applied thereto and showing some of the parts schematically and in operating position;

Figure 2 is a rear elevation looking at the lefthand side of Figure 1 with the central portion thereof broken away and many parts of the loom being omitted for purposes of clarity;

Figure 3 is atop plan view of the rear portion of the loom shown in Figure 1 with the central portion thereof broken away and with many other parts of the loom omitted for purposes of clarity;

Figure 4 is ,an enlarged sectional plan view showing the means for imparting movement to one of the pivoted members on which the closely spaced stationary shafts ,are mounted and is taken looking substantially along the line 4 4 in Figure 1;

Figure 5 is an enlarged vertical sectional view taken substantially along the line 5-5 in Figure 3;

Figure 6 is an enlarged vertical sectional view taken along the line 6-6 in Figure 1;

Figure 7 is an enlarged elevation, with parts in section, looking substantially along the line 'I-J in Figure 2;

V Figure 8 is an enlarged top plan view of the control valve for controlling the flow of compressed vair to the cylinders which control operation of the pivoted members and showing a por tionof the loom side frame in cross-section and is taken looking substantially along the line 88 in Figure 1, but showing the valve in a different po iti n;

Figure!) isa verticalsectional viewthrough the valve taken substantially along the line ;99 in Figures; 4

Figure 10 is a rear elevation of the control valve, with respect to theloom, andiistaken looking substantially along theline l0l0 in Figure Figures 11 and 12 are sectiqnal planviews looking-along the line I I;I in FigureQ and showing thevalve core in diiierentpositions.

he er ns seeeifie to eer in i nume a s Al e H ind a t lri h hen end left-hand side frame members-respectively, of a 9m which rest on the floor. flh e side frame .members 0 and t! are connected at their upper .ent l bv e ereh-en vihe v ieel di ees den portions I3 andi l thereof beingvisiblein Fignres land 2 and bein suitabl seest th 1. 0m si ireme it and 1H respe ti l lfh rre ends of the loom side frame members iii and ii are connected near the front end of the loom by a conventional breast beam l5 suitably secured to the loom side frame members I and H. Near their lower ends, the loom side frame members In and II are connected by front and rear girts, only the rear girt being shown in the drawings and being indicated at Hi. This rear girt is also suitably secured to the loom side frame members In and II.

A conventional rocker shaft H is oscillatably mounted at its ends in the loom side frame members l0 and II and has the lower ends of a pair of horizontally spaced swords 2B fixedly mounted thereon, only one of which is shown in Figure 1. The upper ends of the swords 20 support a con-' ventional horizontally disposed la 2| and a reed cap 22 between which a conventional reed 23 is disposed. The lay 2| and the reed cap 22 are suitably secured, in a conventional manner, to the swords 2|]. Each of the swords is pivotally connected, as at 25, to'the front end of a conventional pitman rod 26 which extends rearwardly and is connectedin the usual manner, not shown, to a conventional crank shaft 21, only one end of which is shown in Figure 1.

The crank shaft 21 is mounted for rotation on the loom frames l0 and I I in a conventional manner, not shown, and is also driven in the usual manner. The crank shaft 21 has a conventional whip roll cam 30 fixedly mounted thereon (Figure 1), the upper surface of which is engaged by awhip roll cam follower 3| rotatably mounted in the front end of a conventional whip roll cam follower arm 32. The arm 32 extends rearwardly and is fixedly mounted on one end of a shaft portion 33 of an eccentric pivot member 34 to which one end of a vibrating whip roll 35 is fixedly secured, as by a screw 36.

It will be observed, in Figure 3, that the opposite end of the vibrating whip roll 35 is secured, as by a bolt 31, to an eccentric pivot member 38. The eccentric pivot members 34 and 38 are oscillatably mounted on one end in the notches of respective whip roll arms 42 and 43 which extend forwardly and are fixedly mounted on a conventional whip roll shaft 44.

Opposed end portions of the whip roll shaft 44 are oscillatably mounted in conventional whip roll shaft bearings 45 and 46 which are usually secured to the proximate surfaces of loom side frame members HI and II respectively. However, in the present instance, the whip roll shaft bearings 45 and 46 are suitably secured, as by bolts 41, to the proximate surfaces of tension unit brackets or support members 50 and respectively. These tension unit support members 50 and 5| extend forwardly and are suitably secured, as by bolts 52 (Figure 1), to the proximate surfaces of the loom side frame members l0 and I respectively. The tension unit support members 50 and 5| are a part of the present invention and the related parts of the present invention will be later described in detail.

A conventional warp beam 55 is mounted for rotation in conventional warp beam bearing members 5511 and 55b (Figure 2) which are suitably secured to the proximate surfaces of the respective side frame members In and II. Warp yarns in the form of a sheet of warp Y extend upwardly from the warp beam 55 and successivel pass over and under a pair of tension or pressure shafts or bars 56 and 5! which also constitute parts of the present invention and the supporting means therefor will also be later described in detail.

The warp yarns Y then extend forwardly and pass above the vibrating whip roll 35 and in engagement therewith and also pass above the whip roll shaft 44. The warp yarns Y extend forwardly from the vibrating whip roll 35 and pass through a plurality of conventional harnesses 60 which are mounted for up and down movement in a conventional manner, not shown. The warp yarns Y then pass through the reed 23 where they are beat up into fabric or cloth F, after which the fabric is pulled over the conventional breast beam 5 and is taken up through the medium of a take-up roll, not shown, controlled by a conventional take-up mechanism to be later described.

The particular type of loom shown in the drawings includes a shipper handle 62 which is adapted to be moved rearwardly to the dotted line position in Figure l, for stopping the loom. This shipper handle is shown in operative position in Figure 1. The shipper handle 62 is provided for the well known purpose of starting and stopping operation of the loom and is oscillatably mounted, as at 63, on the loom side frame member In. The shipper handle 62 extends downwardly and has a link 64 pivotally connected to the lower end thereof and extending upwardly and outwardly therefrom and being pivotally connected to the upper end of a second link 65. This second link 65 is commonly referred to as a hold back pawl link and is a part of the usual type of cloth take up control mechanism associated with looms of a type manufactured by Draper Corporation, Hopedale, Mass, and commonly known as their model XD loom, this type of take-up being generally known as a #15 or #16 silk type take-up.

This particular type of take-up mechanism also includes a hold back pawl 66 which is pivotally mounted, as at 61, on the loom side frame member lo and intermediate the ends of which the lower end of the link 65 is connected. This hold back pawl is adapted to, at times, engage a conventional pick wheel 10 to which intermittent step-by-step rotation is imparted in a conventional manner for taking up the fabric F. The present invention may be controlled through the medium of any type of linkage which may be associated with the shipper handle of the loom, the particular linkage shown in Figure 1 being shown by way of illustration only.

The parts heretofore described, except as otherwise stated, are the usual parts of a loom and it is with these parts that the present invention is adapted to be associated. A detailed description of the improved apparatus for conand associated parts are identical except many of those parts at the right-hand side of the loom in Figure 2 are opposite hand from those parts associated with the left-hand side of the loom and, therefore, only the parts at the right-hand side of the loom, in Figure 2, or at the lower portion of Figure 3' will be described and the parts at the opposite side of the loom will bear the same reference characters with the prime notation added. 7 1

The warp tension unit support member 50 extends rearwardly and is then turned upwardly so that itis substantially L-shaped and the rear 'portion thereof terminates in a higher plane than the whip roll 35 as is clearly shown in Figures 1 and 7. A pivoted tension shaft support, in theform of a cradle broadly designated at I5, is mounted for oscillation, in a manner to be presently described, on the inner face of the bracket 56. Referring to Figures 6 and 7, it will be observed that the cradle I5 has a substantially circular bearing portion I6 integral therewith which is oscillatably mounted in a mating bearing block 'I'I suitably secured, as by a bolt 69, to the inner face of the bracket 56, the bracket 50 being provided with a suitable groove BI and the bearing block I'I having a mating projection 8Ia which fits in the groove BI on the bracket 59 so as to lend rigidity to the bearing block 1! and to prevent relative movement between the bearing block 11 and the bracket 56.

It will also be observed, in Figures 6 and '7, that the bracket 56- is provided with a plurality of bores 82 which are adapted to be slidably penetrated by the bolt 86 for securing the bearing block 11 to the bracket 59 at the desired elevation. The cradle 75 is provided with a pair of spaced substantially semi-circular cavities 84 and 85 which are adapted to receive the corresponding ends of the tension shafts or bars 56 and 5'1 respectively. It is preferable that the inner and upper portions of the cradle I5 be opened so the corresponding ends of the tension or pressure bars 56 and 51 may be placed in the respective cavities 84 and 85 provided therefor and so the pressure bars 56 and 51 may rest upon the bottoms of said cavities.

In order to prevent relative movement between the pressure bars 56 and 51 and the corresponding cradle I5, the shafts or bars 56 and 51 are clampingly secured in the respective cavities 84 and 85 by means of a clamping block 86 disposed between and engaging the proximate portions of the shafts 55 and 5?, the lower surface of the clamping block 66 being adapted to conform to the configuration of the pressure bars 56 and 51. This clamping block 86 is slidably penetrated by a screw 96 which extends between the proximate surfaces of the bars 56 and 51, and in spaced relation thereto, and slidably penetrates a flanged portion 9| of the cradle I5, this flanged portion 9I also defining the bottoms of the cavities 84 and 85. The clamping block 86 is clampingly secured against the upper surfaces of the shafts or bars 56 and 51 by a suitable wing nut 92 threadably mounted on the upper end of the screw 96.

The cradle I5 has a downwardly extending arm 93 integral therewith which extends downwardly and is fixedly connected to the outer or rear end of a piston rod 94, by means of a cuff member 95, this cuif member 95 being secured to the lower end of the arm 93 by a bolt 96. The cuff member 95 is slidably penetrated by a reduced portion 93 of the piston rod 94 (Figure 4) and the cuff member 95 is secured on the reduced portion 91 by a screw I60. The piston rod 94 extends forwardly and slidably penetrates the head IIlI of a pneumatic cylinder I62. The piston rod 94 has a piston I63 fixed on the inner end thereof which is mounted for longitudinally sliding movement in the cylinder I02.

The base of the cylinder I62 has a lug portion I95 extending therefrom which is pivotally connected, as at I96, between a pair of closely spaced ears I5! projecting from and being suitably secured, as by welding, to an angle bracket H0. The piston rod 94, piston I63 and cylinder I62 comprise a preferred form of ram for actuating the tension apparatus. The angle bracket H0 is suitably secured tothe inner face of the warp tension unit support 50 as by bolts I I I. A pipe n5 is connected to the end of the cylinder m2 remote from the piston rod 94 by means of a pipe elbow H6. It is preferable that the pipe H5 is coiled, as at H! or that this H5 is flexible so as to permit movement of the cylinder I02 about its pivot I06.

Referring to Figures 2 and '7, it will be observed that the pipes H5 and H5 extend downwardly and are connected to the branches of a pipe T I20. The pipe H5 extends downwardly and is then .bent horizontally to extend adjacent the rear girt I6 and is connected to the pipe T I20. The pipe T I26 serves as a means of communication between a pipe I2I andthe pipes H5 The pipe I2I is connected, at its end remote from the end which is connected to the pipe T I20, to one end of a suitable control valve broad 1y designated at I22. A suitable means, to be presently described, is provided for operating the valve I22 upon movement of the shipper lever or handle 62 and, referring to Figures 8 to 12, inelusive, there will be observed details of the valve I22. However, it is to be understood that many other types of control valves may be provided in lieu of the valve I22, the valve I22 being provided by way of illustration only.

The control valve I22 comprises an outer casing or housing I24, the lower end of which is threadably penetrated by a tubular pipe fitting I25 which slidably penetrates a valve support bracket I26 suitably secured to the rear edge of the loom side frame member I!) by any suitable means such as a screw I21. The tubular pipe fitting I25 is secured in the bracket I26 by any suitable means such as a set screw I30. The pi e I2I is threadably connected tothe pipe fitting I25.

The valve housing I24 is tubular and its interior is tapered for slidable reception of a tapered tubular valve core I3I having a valve control stem I32 integral therewith or suitably secured in the upper end thereof, as by a pressed fit, and extending upwardly therefrom. This control stem I32 slidably penetrates a gland nut I33 threadably mounted on the upper end of the housing I24 and which secures a gland seal member I34 on the upper end of the housing I24. The tubular valve core I3I is provided with an opening I35 in its wall which is adapted, at times, to register With a port I36 in the wall of the-housing Suitably secured to the upper end of the valve stem I32, as by a screw I3'I, is a control arm I38. One end of a connecting rod I45 is pivotally connected to the free end of the control arm I36, as at I42, and extends forwardly therefrom, as is clearly shown in Figure 1, and is pivotally connected intermediate the ends of the link 65. The valve I22 is shown in an operative position in Figures 1 and 12 and it is shown in an inoperative position in Figures 8' to 11 inclusive. It is thus seen that, upon moving the shipper handle 62 rearwardly to the dotted line position shown in Figure 1, the link 65 will move in a clockwise direction, thus causing the valve control arm I36 to assume substantially the position shown in Figures 8, 9 and 10, at which time the passageway I35 will assume a position in alinement with the port I36 in the valve housing I24 (Figure 11.). However, upon moving the shipper handle 62 to the solid line position shown-in Figure 1,.the valve core 31 will be moved in a clockwise direction from the position shown in Figure 11- to-theposi- 7 tion shown inFigure 12 to thus admit compressed air to the pipe I2 I.

Now, referring to Figure 1, there will be observed a pipe I45 which is connected to an outwardly projecting portion I46 of the valve housing I24 by means of a pipe elbow I41. This projection I46 has a passageway I50 therein to establish communication between the pipe I45 and the interior of the valve I22. The pipe I45 extends downwardly from the control valve I22 and is connected to a suitable source of compressed air in the form of a compressed air tank I5I, this tank being shown schematically in Figure 1.

It is well known to those familiar with the art that during normal operation of a loom, the warp 15 yarns Y are held under a predetermined tension by means of a conventional tension means, not shown, usually associated with the warp beam 55 of the loom. However, in order to avoid the occurrence of set marks at the beat-up point of the lay following periods of either short or long duration in which the loom has not been in operation, it has been found that this will be overcome by relaxing the normal tension on the warp yarns when the loom is stopped, thus permitting the warp yarns to sag intermediate their points of support, which are in this instance, the whip roll 35 and the lay 2|, and then placing them under normal tension upon starting the loom. Therefore, upon moving the Shipper handle 62 to inoperative position or to the dotted line position shown in Figure 1, the valve I22 is closed in the manner heretofore described, that is, the passageway I35 in the valve core I3I registers with the port I36 in the valve housing I24, as shown in Figures 9 and 11, and this prevents the compressed air from the pipe I45 from entering the valve I22,

It is evident that the warp yarns Y may then move the Warp tension shafts or bars 56 and 51 in a counterclockwise direction in Figure 1 or to substantially the position shown in Figure 7, since the compressed air in the cylinders I02, I02 may be exhausted through the respective pipes H5, H5 and thus to the valve housing I24 to be exhausted through the passageway I35 in the valve core I3I and the port I36.

On the other hand, upon moving the shipper handle 62 to the solid line or operative position, in Figure l, the valve I22 will assume an opened position and this will permit compressed air to flow from the source I5I through the pipe I45 to the valve housing I24, which it will enter through the passageway I50. In this instance, the passageway I35 in the valve core I3I will be disposed in alinement with the passageway I50 in the valve housing I24, as shown in Figure 12, and compressed air will thus flow through the tubular valve core I3I and the pipe I2I through the pipe T I and the pipes H5 and H5 to enter the bottoms of the respective cylinders I02 and I02. This will cause the respective pistons I03 along with their piston rods 94 to move outwardly or from right to left, in Figure 4, to impart movement to the cradle I5 in a clockwise direction in Figure 1 or in counter-clockwise direction in Figure 7.

It is evident that, with movement of the cradles I5 and I5 in a clockwise direction in Figure 1', the tension shafts or bars will also move in the same direction and will create additional tension on the warp yarns Y.

It is thus seen that we have provided an improved means for creating a normal amount of tension in the warp yarns during periods in which 75 the loom is in operation and said means being automatically operable to simultaneously relax the tension in the warp yarns upon moving the shipper handle to inoperative position for stopping the loom.

In the drawings and specification, there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

We claim:

1. In a loom having an oscillatable lay and also having a cloth take-up mechanism and also having a warp beam and also having a whip roll and warp yarns extending from the warp beam to the whip roll and progressively to the lay, said loom also having a shipper handle for stopping and starting the loom, means automatically operable upon moving the shipper handle to inoperative position for relaxing the normal tension in the warp yarns and said means also being automatically operable for creating normal tension on the warp yarns upon moving the shipper handle to operative position for'starting the loom, said automatically operable means comprising a pair of relatively closely spaced bars disposed in advance of the whip roll and over and under which the warp yarns are adapted to pass in their course from the warp beam to the whip roll, means supporting said bars in fixed relation to each other, said means supporting said bars being pivotally supported on said loom and means automatically operable upon movement of the shipper handle to operative position to move the pivoted means supporting said bars about its axis to, in turn, move said bars about the said axis for creating a normal tension upon said warp yarns and means automatically operable upon moving the shipper handle to inoperative position for releasing the means moving said pivoted means for supporting the bars to thus relax the tension in the warp yarns between the warp beam and the lay to thereby prevent the occurrence of set marks in the fabric woven thereby.

2. In a loom having a lay and also having a cloth take-up means and also having a whip roll and also having a warp beam and warp yarns extending from the warp beam over the whip roll and being suspended between the whip roll and the lay, said loom also having a shipper handle for starting and stopping the loom, warp tension applying means responsive to movement of the shipper handle to operative position tor creating a normal amount of tension in the warp yarns comprising a first tension bar and a second tension bar extending transversely of the loom, pivoted means supporting the first and the second tension bars in closely spaced relation to each other, a ram connected to at least one of the pivoted means, said warp yarns being adapted to pass from the warp beam above the first of said tension bars and beneath the second of said tension bars and then over the whip roll in its course to the lay, a source of fluid under pressure, a pipe connection between the source of fluid under pressure and the ram, valve means interposed in said pipe connection and means responsive to movement of the shipper handle from inoperative to operative position for opening said valve to permit the fluid under pressure to flow from its source to the ram to, in turn, impart movement to the pivoted means supporting said bars and causing said bars to impart a normal tension to said warp yarns and means automatically operable upon movement of the shipper handle to inoperative position for closing said valve and to thus prevent the flow of fluid to the ram thereby relaxing the pressure on said bars and relaxing the tension in the warp yarns during periods in which the loom is not operating.

3. In a loom having an oscillatable lay and having cloth take-up means thereon and also having a whip roll and also having means for delivering warp yarns to the whip roll and said warp yarns extending from said delivering means over the Whip roll and to said lay, a pair of closely spaced tension shafts extending transversely of said warp yarns and over and beneath which the warp yarns are adapted to pass from said delivering means to the whip roll, a cradle pivotally supported on each side of said loom and supporting each end of said tension shafts, an extension arm on at least one of said cradles, a source of compressed air, at least one ram, a connection between the ram and the free end of said arm, a pipe connection between the source of compressed air and the ram and valve means interposed in said pipe connection, means automatically operable upon starting the loom for opening said valve means to permit compressed air to flow to said ram from the source to cause said ram to impart movement to the cradles and to the shafts for creating tension on the warp yarns and means automatically operable upon stopping the loom for closing the valve means to prevent the flow of compressed air to the ram to permit the warp yarns to move the tension shafts in their cradles thus relaxing the tension in the warp yarns.

4. In a loom having an oscillatable lay and also having a cloth take-up mechanism and also having a whip roll and also having a warp beam and warp yarns extending from the Warp beam to the whip roll and progressively to the lay, an improved tension control means for the warp yarns comprising a pair of transverse tension bars disposed in advance of the whip rol1 and over and. under which the warp yarns are adapted to pass successively from the warp beam to the whip roll, means supporting said tension bars for movement about a common axis in off-set relation to the axis of the tension bars comprising a tension unit support bracket secured to each side of the loom and extending rearwardly therefrom, a cradle pivotally mounted on each of the tension unit supports, each of said cradles being provided with a pair of spaced open topped cavities therein for reception of the corresponding ends of the tension bars, means for clampingly securing said tension bars in the cavities in said cradle and means automatically operable upon starting the loom for imparting movement to said cradles about their axis to, in turn, cause the tension roll to move about the axis of said cradles for creating a normal tension in the warp yarns, and means automatically operable upon stopping the loom for relaxing the means which impart movement to the cradles to thereby permit the cradles to return to a, normal position for relaxing the tension in the warp yarns.

5. In a loom having an oscillatable lay and also having a cloth take-up mechanism and also having a whip roll and also having a warp beam and warp yarns extending from the warp beam to the whip roll and progressively to the lay, an improved tension control means for the warp yarns comprising a pair of transverse tension bars disposed in advance of the whip roll and over and under which the warp yarns are adapted to pass successively from the warp beam for movement about a common axis in off-set relation to the axis of the tension bars comprising a tension unit support bracket secured to each side of the loom and extending rearwardly therefrom, a cradle pivotally mounted on each of the tension unit supports, each of said cradles being provided with a pair of spaced open topped cavities therein for reception of the corresponding ends of the tension bars, means for clampingly securing said tension bars in the cavities in said cradle and means automatically operable upon starting the loom for imparting movement to said cradles about their axis to, in turn, cause the tension roll to move about the axis of said cradles for creating a normal tension in the warp yarns, and means automatically operable upon stopping the loom for relaxing the means which impart movement to the cradles to thereby permit the cradles to return to a normal position for relaxing the tension in the warp yarns, at least one of said cradles having an arm extending therefrom, a ram carried by the loom and being connected at one end thereof to the free end of said arm, means responsive to starting the loom for actuating said ram to move the cradles about their axis for creating tension in the warp yarns through the medium of the tension bars, and means responsive to stopping the loom for releasing the ram to permit the warp yarns to move the tension bars in the opposite direction for relaxing the tension in the warp yarns.

6. In a loom having an oscillatable lay and also having a cloth take-up mechanism and also having a whip roll and also having a warp beam and warp yarns extending from the warp beam to the whip roll and progressively to the lay, an improved tension control means for the warp yarns comprising a pair of transverse tension bars disposed in advance of the whip roll and over and under which the warp yarns are adapted to pass successively from the warp beam to the whip roll, means supporting said tension bars for movement about a common axis in off-set relation to the axis of the tension bars comprising a tension unit support bracket secured to each side of the loom and extending rearwardly therefrom, a cradle pivotally mounted on each of the tension unit supports, each of said cradles being provided with a pair of spaced open-topped cavities therein for reception of the corresponding ends of the tension bars and means automatically operable upon starting the loom for imparting movement to said cradles about their axis to, in turn, cause the tension roll to move about the axis of said cradles for creating a normal tension in the warp yarns, and means automatically operable upon stopping the loom for relaxing the means which impart movement to the cradles to thereby permit the cradles to return to a normal position for relaxing the tension in the warp yarns.

THOMAS J. WILLIS. WILLIAM A. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,532,667 Baker Apr. '7, 1925 1,603,708 Northrop Oct. 19, 1926 1,628,815 Wakefield May 17, 1927 

